Hello, our mobile site speed is really slow (19). It looks likes unused JavaScript is the number one issue, but also Render Blocking Resources and unused CSS.
Just hoping for some recommendations on where to start. Here are the details from PageSpeed:
Most ecommerce sites score low with that tool, it’s common if you’re using 3rd party apps especially. Info about that here: https://speedboostr.com/google-psi-for-shopify.
Few tips to help guide your performance optimization quest:
1) Focus first on what you can reasonably optimize on a Shopify site. To see that, run your site through the Shopify Analyzer. That’s a free tool my team built for the Shopify community - the scoring and recommendations are based on over 1,000 Shopify sites we’ve optimized.
You can use that in tandem with our free guide to optimize your site: https://speedboostr.com/shopify-optimization. If you have a developer share that with them. If you don’t have a developer on the team, you should still be able to perform some of the optimizations yourself. We try to make it easy 
2) After optimization, test your site on a slow connection. If you still feel it’s too slow, you can look at either removing apps (not recommended if they’re generating revenue) or invest in hardcoding store facing apps (integrate the feature directly into your theme code instead of relying on 3rd party resources).
3) “unused JavaScript and css” is good to take care of on your Shopify site if it’s the result of wasted resources. For example, if you’ve installed a store facing app that inserted some code into your theme, and then deleted the app, unless you remove the code manually it will still be in your theme loading (because apps lose access when you delete them). This doesn’t happen to all apps, but worth checking your theme.liquid file at least to see if you recognize any old app code. (we also have a thorough App Analysis service if you don’t feel like digging in your code).
If you’re talking about “unused javascript and css” inside your files, for example your theme.js file, that’s going to be a major project to deconstruct your theme files and conditionally load only the code required for each separate template of your site. That will yield small gains but be an expensive project, probably not a positive ROI.
4) “Render Blocking Resources” can be misleading. It’s good to defer resources that aren’t critical to page load to the end of the page. But the challenge with a template site with 3rd party resources is that you can shoot yourself in the foot by deferring a resource you thought wasn’t needed, but then actually is. You also can’t control this if apps are loading the resources in the head (which often is by design).
For this one, I recommend loading any non-critical resources at the end of the page, but make sure you test thoroughly before publishing your theme.
You can implement techniques to load only the resources needed to render above the fold content, in the head… but again this is a time (or money) expensive process that also generates maintenance any time you change your site or sometimes install a new app. Usually not worth the ROI unless you’re doing massive traffic volumes.
Hi @JeffYVH
There are many factors that slow down the page speed.
For the unused CSS and JS, you can check what you are using and what is not used.
Shopify themes include various features to customize for the client’s usage. Therefore, there can be some unnecessary CSS/JS in your theme files.
Also, I found that you are using a Vimeo player in your store and it can slow down the loading speed.
Try to lazyload it and it will help you increase the speed.
Best Regards
Hello @JeffYVH ,
You need to work on your website performance’s speed. Low mobile page speed may kill your traffic and affect your conversion.
In order to Improve website speed we need to:
By fixing these issues, your website speed score can definitely improve. For more details please check and select the plan you wish to select -
https://www.oscprofessionals.com/shopify-performance-optimization/
If anything is missed out or unclear then don’t hesitate to ask
Thank You!
@JeffYVH I hope you were able to solve your speed issues, if not the recommendations I gave will help you out.
I want to give a quick heads up on the recent poster, @oscprofessional - they’ve been caught stealing and breaking Shopify terms of service on multiple occasions. (Details here: https://speedboostr.com/shopify-partners-caught-stealing/#copyright-osc)..)
I assume you don’t want criminals having access to your business / data, I know I wouldn’t.
If my team’s not a good fit and you still need help, you can also check the Shopify Experts directory - Anyone can be a Shopify Partner, but to get the Shopify Expert badge is more difficult, there’s a vetting process to ensure quality and ethics.
Good luck on the speed and overall store success.
